Which way should skylight hatches face?

[erps]

Our boat has five Bomar hatches of varying sizes. The three forward ones have the hinges on the back. The two aft ones have the hinges forward. That arrangement works for us while coastal cruising and at anchor for ventilation purposes. We dog down the forward ones while underway. Do any of you blue water guys have any strong opinions on which way the hatches should open?

[Stillraining]

Thats a great question Ray ..and the guy that wrote the dry boat book prefers hinges on forward edges or rear opening for two reasons..Boats will piont into the wind at anchor so air running over a cracked hatch will create a suction to pull and move air throughout the boat ventilating it yet providing still a good deal of protection from driving rain..and secondly what you mentioned off shore getting green water over the deck if a hatch should pop open a forward facing one is going to funnel a ton of water below...a rear facing on would get slammed shut. I think he has good points.

I believe all of mine are forward facing..

PS: did you notice we had our first sail..

[Zanshin]

New Zealand requires hatches hinged at the front for boats registered there. The ISAF Rules state:

3.08.2 A hatch shall be:
a) so arranged as to be above the water when the
hull is heeled 90 degrees. Hatches over lockers
that open to the interior of the vessel shall be
included in this requirement. A yacht may have a
maximum of four (two on each side of
centerline) hatches that do not conform to this
requirement, provided that the opening of each
is less than 0.071 sq m (110 sq in). Effective for
boats of a series begun after January 1, 2009, a
written statement signed by the designer or
other person who performed the downflooding
analysis shall be carried on board. For purposes
of this rule the vessel’s displacement condition
for the analysis shall be the Light Craft Condition
LCC (in conformity with 6.3 of the EN ISO 8666
standard and 3.5.1 of the EN ISO12217-2
standard).
Mo0,1,2,3,4
b) permanently attached **
c) capable of being firmly shut immediately and
remaining firmly shut in a 180 degree capsize
(inversion)

[sailingdog]

I believe the reason NZ has that requirement is that a wave sweeping the deck and cabintop is likely to slam the hatch shut rather than tear it off and fill the boat with water.

[Faster]

This has been discussed at length in a previous thread... and the consensus was that there's an 'offshore" ideal and a coast "anchor every day" ideal. The offshore ideal is the "self closing" nature of forward hinged hatches.. but they are not as effective at ventilation. Also if you're doing regular sail changes, if the hatch doesn't open fully flat then stuffing a sail below is a bit more awkward with a forward hinged hatch.

Someone (not sure which manufacturer) produces double hinged models that can be used either way... makes sense to me.

[hellosailor]

Opening forward = better ventilation on the hook and less underfoot for repeated foredeck work with a chute, etc. for racing around the cans.

Opening rearward = safer at sea if you stuff the bow in a wave

Which is why several ocean racing sponsors require them opening rearward now. And as Faster notes, there are also some patent hatches that can be opened in either direction, needless to say more expensive.

[sailingdog]

Unfortunately, for the cruising sailor, the ones that can open both fore and aft are also much easier to break into IIRC.

Originally Posted by hellosailor

Opening forward = better ventilation on the hook and less underfoot for repeated foredeck work with a chute, etc. for racing around the cans.

Opening rearward = safer at sea if you stuff the bow in a wave

Which is why several ocean racing sponsors require them opening rearward now. And as Faster notes, there are also some patent hatches that can be opened in either direction, needless to say more expensive.

[Maine Sail]

Ours open aft. This is the first boat we've owned with this configuration and I will NEVER go back to forward opening hatches.

We find, especially in Maine, that the boat stays considerably drier in damp weather yet we can still get tons of ventilation through the chimney effect! This boat develops very little interior mold and stays very dry compared to boats we've owned with forward opening hatches..

If we ever buy another boat, and the hatches open forward, I will actually go through the hassle of flipping them around!

[JohnRPollard]

Originally Posted by Faster

Someone (not sure which manufacturer) produces double hinged models that can be used either way... makes sense to me.

That would be the Bomar cast hatches. Ours can be quickly reversed by swapping the hinge pins in about ten seconds. There are two sets of "dogs" on the inside. For general use, you only need to dog the set at the opening end. For serious conditions, you can dog all four and apply even pressure all around the gasket.

You can see the forward hinge in this photo, without the pins. We have the pins in the aft hinge for forward opening. I have tried it both ways and prefer the forward opening arrangement for the kind of sailing (coastal) that we do.

[GeorgeB]

You guys with the rearward opening hatches, how do you squirrel a spinnaker without it getting caught on the hatch or you (the forepeak man) inadvertently stepping on the lens and breaking the hatch? I have done take-downs in squalls with a forward opening hatch without a problem and the vast majority of water down the hatch was rain.